In wireless data transfer, a node communicates wirelessly with a network. Both the node and the network have transceivers. A typical communications scheme involves multiple nodes with a single radio frequency or narrow band of frequencies. The system capacity, as expressed in bandwidth, is limited so that all of the nodes are unable to communicate at the same time with the network. Because of this limitation, a node is unable to have a dedicated communication channel or link to the network; the channels must be shared among the nodes.
To communicate with a network, a node requests a channel from the network. If the request is granted, the channel is established and communication between the node and the network can occur. The request is denied if no channels are available, as all channels will be in use. If the request is denied, then the node will need to continue requesting a connection until the request is granted. This would come when channels are freed.
This is not a particularly efficient method of communicating. A node can tie up a channel even if the channel is not being used. The channel remains open until either the node or the network closes the channel. The availability of channels becomes complicated if the nodes are mobile and move in and out of communication range. A channel may remain open even if the node moves out of communication range. If the node moves back in range, that node may request another channel, thereby tying up two channels. In fringe areas, a node may repeatingly move in and out of range, opening many channels, while not closing any.
What is needed is a more efficient system of managing channels in a communication system.